Jen Bradford - you might first try scrubbing baking soda and warm water on the item. Rinse, Repeat. If you want a stronger solution - then Vinegar is key. It does wonder at removing smells from Tupperware, and just might do the trick on silicone. You could soak it. (Some prefer lemon over vinegar, but though lemon is one of my fave cleaners, vinegar does wonders with certain lingering smells). After that I'd leave it directly in the sun for a while. The sun is a perfect, natural way to kill odors. Good luck!